Hi all I have a client sever application ,as iam sending buffer from one ssytem to another is is working perfectly ok for sometime but after sometime i get a error .exe has triggered a breakpoint I checked on the call stack where i got Code: ntdll.dll!7c901230() [Frames below may be incorrect and/or missing, no symbols loaded for ntdll.dll] msvcr90d.dll!_CrtDbgBreak() Line 89 In my Output window iam getting this mesg Code: ScenGen.exe': Loaded 'D:\SGenerator\Debug\ScenGen.exe', Symbols loaded. 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\ntdll.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\kernel32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\opengl32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\msvcrt.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\advapi32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\rpcrt4.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\gdi32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\user32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\glu32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\ddraw.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\dciman32.dll' 'ScenGen.exe': Loaded 'D:\SGenerator\Debug\fastdb.dll', Symbols loaded. 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\wsock32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\ws2_32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\ws2help.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\WinSxS\x86_Microsoft.VC90.DebugCRT_1fc8b3b9a1e18e3b_9.0.21022.8_x-ww_597c3456\msvcp90d.dll', Symbols loaded. 'ScenGen.exe': Loaded 'C:\WINDOWS\WinSxS\x86_Microsoft.VC90.DebugCRT_1fc8b3b9a1e18e3b_9.0.21022.8_x-ww_597c3456\msvcr90d.dll', Symbols loaded. 'ScenGen.exe': Loaded 'C:\WINDOWS\WinSxS\x86_Microsoft.VC90.DebugMFC_1fc8b3b9a1e18e3b_9.0.21022.8_x-ww_2a62a75b\mfc90d.dll', Symbols loaded. 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\shlwapi.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\msimg32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\WinSxS\x86_Microsoft.Windows.Common-Controls_6595b64144ccf1df_6.0.2600.2180_x-ww_a84f1ff9\comctl32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\oleaut32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\ole32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\WinSxS\x86_Microsoft.VC90.MFCLOC_1fc8b3b9a1e18e3b_9.0.21022.8_x-ww_11f3ea3a\mfc90enu.dll', Binary was not built with debug information. 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\uxtheme.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\iglicd32.dll', Binary was not built with debug information. 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\igldev32.dll', Binary was not built with debug information. 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\mcd32.dll' 'ScenGen.exe': Unloaded 'C:\WINDOWS\system32\mcd32.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\urlmon.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\version.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\asycfilt.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\mlang.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\mswsock.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\hnetcfg.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\wshtcpip.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\dnsapi.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\winrnr.dll' 'ScenGen.exe': Loaded 'C:\WINDOWS\system32\wldap32.dll' [B]Second Chance Assertion Failed: File f:\dd\vctools\vc7libs\ship\atlmfc\src\mfc\wincore.cpp, Line 310 ScenGen.exe has triggered a breakpoint [/B] Does anyone knows whats this problem is .I s it because earlier program was working in vs 2005 & now i have converted to vs 2008 You suggestion will be helpful thanks